Temperature Dependence of Short-Range Order inβ-Brass

Abstract

Critical scattering of neutrons around the superlattice reflections (1, 0, 0) and (1, 1, 1) from a single crystal of $\beta$-brass has been measured at temperatures from 2 to 25°C above the transition temperature. The temperature dependence of the critical peak intensity, proportional to the susceptibility $\chi$, and that of the inverse correlation range ${\kappa }_1$ were, respectively, fitted to the power laws $\chi \propto {\left(\frac{(T-T_c)}{T}\right)}^{-\gamma }$ and ${\kappa }_1=\left(\frac{k}{a}\right)\times {\left(\frac{(T-T_c)}{T_c}\right)}^{\nu }$, yielding $\gamma =1.25\mathrm{}\pm 0.02$, $\nu =0.65\mathrm{}\pm 0.02$, and $k=3.0\mathrm{}\pm 0.3$. Here $a$ is the cube edge of the unit cell. These results agree with the theoretical predictions of the Ising model.